The invention concerns a composite profile having a rail-like carrier profile extruded from light metal material as well as a profile strip made of a harder metal and resting on its top surface. The invention covers a method for manufacturing such a composite profile.
DE 24 32 541 A1 shows a method for manufacturing conductor rails from a carrier profile and at least one overlay which forms at least part of the surface of the carrier profile serving as the conductor and which consists of a profile strip of a different metal to the covering profile having high abrasion resistance. The free cross-sectional ends of the flat profile strip are formed by edge surfaces which are inclined towards each other and which in the fitted position fit snugly against correspondingly inclined edge strips of a depression in the carrier profile which receives the profile strip. During an extrusion operation the carrier profile is produced by forcing a block out through the shaping cross-section of an extrusion die, and at the same time the profile strip passes through the die opening or shaping cross-section parallel to the longitudinal axis of the die. During the extrusion operation an intimate metallic bond is formed between the two profile components. For instance, when the conductor rail is used to electrify rail-mounted vehicles, in cases of particularly high load the profile strip comes away from its light metal carrier profile in the long term in spite of the intimate metallic bond.
DE 198 40 720 A1, which describes a steel strip with flat bottom and steel strip arms integrally formed thereon at right angles, refers to the document described above. These arms are provided with recesses for receiving rivets, bolts, screws or caulked joints. Those steel strip arms are inserted in slots at right angles to the steel strip bottom or to the top surface of the carrier profile, and then fixed with the rivets or the like to the inner wall of the slot.
In DE 44 10 688 A1 can be found a composite profile having a carrier profile made of light metal and a profile strip connected thereto. The latter spans the surface of a rail head of the carrier profile, is shaped like a channel in cross-section and comprises in its side arms, projecting at a distance from each other from its inner surface on the side of the supporting body, shaped portions which are embedded in the supporting body. These shaped portions define undercut gaps which are filled by the metallic material of the supporting body in form-fit relationship. This form-fit connection is not subject to the faults described for the metallic bond.
A composite conductor rail element for supplying power to a rail vehicle with a coating made of a material of high mechanical strength which is rigidly fixed to a rod made of material which is a good conductor of electricity and which forms the sliding or contact surface for current collectors of the vehicle, is disclosed by DE 25 46 026 A1. The coating is fixed to the conductive rod which serves as the carrier by wedging or squeezing the edges of the coating into the conductive rod. In the coating is formed at least one indentation which runs in the longitudinal direction and which penetrates as far as the conductive rod. For wedging the edges of the coating, in the conductive rod is provided a groove which is divided by a lip. The latter leads to wedging of the coating on the conductive rod as soon as it has been at least partially wrapped round and pressed against the edge of the coating.
Conductor rails of which the wear components are attached to the live carrier profile by screws or additional inserts passing through them laterally, also proved to be disadvantageous. Other known manufacturing methods can disadvantageously lead to undulations on the surface of the covering profile, caused by caulking or stamping the carrier profile in stages.
Knowing this state of the art, the inventor set himself the aim of more extensively improving the connection between carrier profile and profile strip, while retaining the special capacity for economical manufacture.